A joint yoke is known from DE 29 00 846 A1. Here, the joint yoke is made from sheet metal.
Universal joints have two joint yokes. The yoke arms of the two joint yokes are connected in an articulated manner to each other via a journal cross assembly. A journal cross assembly has a cross with four journals projecting from a base body. Two journals, respectively, are arranged in a centered manner in pairs on a common bearing axis. The journals are supported, via bearing arrangements, in the bearing bores of the yoke arms. Often rolling member bearings are used that are arranged in bearing bushes. The bearing bushes are accommodated in the bearing bores. The rolling members of a rolling member bearing roll on an inner bearing face, formed by the respective journals, and on an outer bearing face, formed by the bearing bush inserted in the bearing bore, or by the bearing bore itself. Zones of higher loading are produced during the transmission of torque from one of the two joint yokes to the other joint yoke. In this case, stiffer components of the yoke arms and areas with a larger lever arm of the torque transmission absorb a larger part of the loading. These zones of higher loading are arranged, relative to the axis of rotation, radially outwards, at the ends of the journals remote from the body of the journal.
DE 103 03 291 A1 discloses a cross to achieve a more constant load distribution. The inner bearing faces of at least two journals are arranged on a common journal axis and are represented, respectively, by an outer circumferential face of a journal or by an outer circumferential face of a bushing mounted on the journal. The inner bearing faces have, respectively, one first bearing face portion and a second bearing face portion. The first bearing face portion is arranged on a rotational symmetrical envelope face arranged coaxially to the respective journal axis. The second bearing face portion is arranged within the envelope face that extends in direction from the base body to the respective free end with a continuously decreasing distance to the respective journal axis. The second bearing face portion extends across a portion of the circumference of the respective journal.
The second bearing face portion extends in the axial direction in relation to the respective journal axis with a continuously decreasing distance to the journal axis. Thus, a load distribution of the bearing forces is ensured in the axial direction. Furthermore, the second bearing face portion extends only along a part of the outer circumferential face. Thus, a reduction of the maximum loadings is achieved in the main loading zone.
However, it is disadvantageous that the journal of the journal cross assembly has to undergo a relative cumbersome manufacturing process in order to form the corresponding bearing face portions.
DE 199 53 963 A1 discloses a solution where recesses are provided in the cylindrical wall of the bearing bores. The recesses extend along a portion of the circumference and have, in the axial direction of a journal axis, a varying depth. The journals of the cross are mounted in a bearing bush via rolling member bearings. The bearing bush is accommodated in the bearing bore. Thus, in the area of the recesses that are situated in the area of the main loading zone a deformation of the bearing bush occurs so that the maximum loadings are reduced.
DE 1 425 952 A1 illustrates a shaft to reduce the maximum loadings in a rolling member bearing. The shaft is oval in cross-section and is supported in a ring in a rolling member manner. In the area of the main loading zone, the shaft has the largest radius of curvature. Thus, the bearing load is distributed to more rolling member bodies than in an embodiment where the shaft is formed with a circular cross-section. The disadvantage is, however, that in the axial direction of the shaft no bearing load distribution is achieved.
DE 29 33 505 A1 illustrates a journal cross assembly with journals rollingly supported in bearing bushes. The bearing bushes are accommodated in bearing bores in the joint yokes. The outer circumferential faces of the bearing bushes are essentially cylindrical and have flatten areas in the area of the main loading zones. The flatten areas extend along a part of the circumference and in the direction of the journal axis. Starting from a base body where the journals are formed, the flatten areas approach in a direction to the respectively free end of the journal along the journal axis.
The bearing load distribution in the axial direction in relation to the journal axes DE 1 122 781 B shows a cross with journals. The outer circumferential face is conically formed. In this case, however, no bearing load distribution is achievable in the circumferential direction. Furthermore, the rolling member bodies are at low loading not abutting across their entire longitudinal extension the bearing face of the bearing bore.